Self-sealing cap



' Feb. '16, 1942'.

L A. M. ANDREWS SELF-SEALING CAP Filed Julie 10, 194;

. IN VEN TOR.

' ATTORNEYS.

Patented Feb. 10, 1942 UNITED STATES PATENT OFFICE SELF-SEALING CAPAlton M. Andrews, Modesto, Calif. Application June 10, 1940, Serial No.339,823

1 Claim.

This invention relates to a self-sealing cap designed primarily for useon collapsible dispensing tubes such asthose in which are sold shavingcream, tooth paste, etc.

Heretofore caps. having valved outlets have been produced but in everyinstance, as far as I am aware, they have depended upon the resiliencyof the material from which they are made, in order to effect closing oftheoutlet in the cap after material has been dispensed.

It has been found in practice that efficient caps of this type cannot beproduced commercially because the slits or openings provided therein,regardless of their shape, cannot be individually cut but must be moldedin the cap when it is vulcanized or cured and, consequently, must remainpartly opened with the result that there is no resiliency in the captending to close the outlet so as to seal the cap.

An object of the present invention is to provide a resilient cap soshaped, when molded, that application of the cap to the neck of a tubeor other container, will change the shape of the cap in such a manner asto create a tension in two directions close to a slit constituting theoutlet opening in the cap, and, although this slit is formed by moldingand is slightly parted or open in the cap before its application, thedistortion of the cap when being applied to the neck of the container,will be such as to thrust through the material of the cap against thesides of the slit, tending to close them together while at the same timea pull will be exerted upon the ends of the slit, tending to stretch itand thereby further insuring tight closing of the opening when the capis in position on the container.

With the foregoing and other objects in View which will appear as thedescription proceeds, the invention consists of certain novel details ofconstruction and combinations of parts hereinafter more fully describedand pointed out in the claim, it being understood that changes may bemade in the construction and arrangement of parts without departing fromthe spirit of the invention as claimed.

In the accompanying drawing the preferred form of the invention has beenshown.

In said drawing Figure 1 is a central vertical transverse sectionthrough the cap showing the shape thereof 7 prior to application to theneck of a container.

Figure 2 is a section on line 22, Figure 1.

Figure 3 is a bottom plan view of the cap.

Figure 4 is a section on line 4-4, Figure 1.

Figure 5 is a section through the cap similar to Figure l but showingthe cap distorted and in position on the neck portion of a containerthereby to close together the sides of the outlet slit. Figure 6 is asection on line 6-B, Figure 5. Referring to thefigures by characters ofreference, l designates the dome-like end of the cap from which isextended an integral skirt 2 interiorly screw-threaded as at 3. Thesocket or recess in the cap having the threaded wall, terminates at ashoulder 4 and extending from this shoulder and through the center ofthe domelike end I, is an opening 5. At the outer end of this openingthere is provided an outlet slit 5. The inner end of the opening, whichis substantially in line with the shoulder 4, is substantially circularbut as the opening progresses toward the slit, it assumes gradually asubstantially elliptical shape as indicated in Figure 4, its opposedwalls' gradually merging into the substantially straight sides of theslit 6.

The base or open end of the 'cap is normally in the form of an ellipse,as shown at l, the long diameter of this ellipse being parallel with thelong dimension of the slit 6 while the short diameter of the ellipse isat right angles to the long dimension of the slit 6.

The wall of the cap is thickened by molding elongated nodes 8 thereon,these nodes extending above and below the plane of shoulder 4 andtapering down to the main surface of the cap. Two of the nodes arebisected by the plane in which are located the long dimension of slit 6and the long diameter of the elliptical base 1.

The other nodes 8 are intersected by a plane at right angles to the slit6 and elliptical base 5. Thus the cap is provided with an increasedamount of material below the ends of the slit 5 and also below the sidesthereof.

Obviously a cap such as herein described can be readily molded, the slit6 being also produced by the molding operation, this being possible dueto the fact that it is not essential that, on the completion of themolding operation, the opposed walls of the slit be pressed together.Thus caps can be produced rapidly and at very low cost.

When it is desired to apply a cap to the neck portion N of a container Cthe elliptical open end of the cap is distorted from its normal shape,shown in Figure 3, until it is made substantially round so that it thuscan be placed on neck N and, if desired, screwed thereonto. In spreadingapart the elliptical open end of the cap along the small diameterthereof, a thrust is set up through the material of the cap within thosesides thereof being pulled apart at the open end ameter thereof, will bepulled toward each other,

thus causing the adjacent portions of the material in the wall of thecap to be pulled -or stretched. This action will be transmitted to theends of the slit 6 with the result that said slit will be stretched inthe direction of its length while its opposed walls are being pushedtogether.

Consequently an effective seal is setup due to this action within thewalls of the cap.

The operation explained might be described as a leverage action.Considering those sides of the walls in line with the short diameter ofthe open end of the cap as levers with the thickened nodes 8 thefulcrums and viewing also as levers those portions of the walls and thenodes beyond or in linewith theends of slit 6, it will be noted that twoof these levers will swing apart at the centers of the sides of theelliptical opening at the base while their opposite ends will thrustagainst the sides of slit 6 and, during this oper' ation, the levers atthe ends of the elliptical opening will swing toward each other at oneend while the other ends thereof pull on the ends of slit 6 and tend tostretch the slit.

When the container is collapsed or a portion of the contents areotherwise caused to exude through neck N, the exuding portion will enterthe opening and press against the outwardly converging opposed wallsthereof, shown in Figures 1 and 5, at the same time causing the slit 6to open laterally against the pressure being exerted by the adjacentportions 0! the cap. As soon as the pressure against the cap by thematerial being dispensed, has been removed, the pressure of the materialof the cap will be sunlcient to force the side edges of the slittogether, thereby sealing the cap against the admission of dust,moisture, etc.

What is claimed is:

The combination with the neck of a container, said neck having an outletopening, of a selfsealing cap of resilient material having a recess inone end for receiving the neck of the container, the other end of thecap being dome-like and having a slit, there being an opening in the capleading from the recess to the slit and of greater diameter at therecess than the opening in said neck, the recessed end of the cap beingelliptical with its long dimension in a plane extending longitudinallyof the slit, said cap providing walls for the opening which convergealong curved lines to the sides of the slit, said converging wallscooperating with the outer surface of the cap at the sides of the slitto define opposed edges positioned to close together when opposedportions of the cap are pressed toward each other at the slit, thoseportions of the cap wall between the sides of the slit and the recessedend being thickened whereby said wall is stiffened to transmit thrust tothe sides of the slit from the corresponding sides of the recessed endwhen said end is spread laterally from normal elliptical shape, thoseportions of the cap wall between the ends of the slit and the recessedbase being thickened, whereby said portions are stiffened to transmit apulling force to the ends of the slit to elongate the slit when therecessed end is spread laterally from normal elliptical shape.

ALTON M. ANDREWS.

